Mitsubishi Electric PAC-AK53BC, PFC-AK51BC, PAC-AK52BC, PAC_AK32BC, PAC-AK31BC Installation Manual

2

Contents

1. Safety precautions .............................................................................................2

2. Selecting a location for installation ....................................................................

2

3. Conrming supplied accessories .......................................................................

3

4. Dimensions and required servicing space of Branch Box .................................

3

5. Refrigerant piping ..............................................................................................

4

6. Mounting the Branch Box ..................................................................................

5

7. Installing refrigerant piping

.................................................................................5

8. Installing drain piping .........................................................................................

6

9. Electrical work

....................................................................................................7

10. Test run

..............................................................................................................9

1. Safety precautions

► Before installing the unit, make sure you read all the “Safety precau-

tions”.

► Please report to your supply authority or obtain their consent before

connecting this equipment to the power supply system.

After installation work has been completed, explain the “Safety Precautions,” use,
and maintenance of the unit to the customer according to the information in the
Operation Manual and perform the test run to ensure normal operation. Both the
Installation Manual and Operation Manual must be given to the user for keeping.
These manuals must be passed on to subsequent users.

: Indicates a part which must be grounded.

Warning:

Carefully read the labels affixed to the main unit.

Warning:

Describes precautions that must be observed to prevent danger of injury or

death to the user.

Caution:

Describes precautions that must be observed to prevent damage to the unit.

This installation manual is only for the branch box installation. In installing the indoor units and outdoor units, refer to the installation manual attached to

each unit.

Warning:

• Ask a dealer or an authorized technician to install the unit.

• For installation work, follow the instructions in the Installation Manual and
use tools and pipe components specifically made for use with refrigerant
specified in the outdoor unit installation manual.

• The unit must be installed according to the instructions in order to minimize
the risk of damage from earthquakes, typhoons, or strong winds. An incor­rectly installed unit may fall down and cause damage or injuries.

• The unit must be securely installed on a structure that can sustain its
weight.

• If the air conditioner is installed in a small room, measures must be taken
to prevent the refrigerant concentration in the room from exceeding the
safety limit in the event of refrigerant leakage. Should the refrigerant leak
and cause the concentration limit to be exceeded, hazards due to lack of
oxygen in the room may result.

• Ventilate the room if refrigerant leaks during operation. If refrigerant comes
into contact with a flame, poisonous gases will be released.

• All electric work must be performed by a qualified technician according to
local regulations and the instructions given in this manual.

• Use only specified cables for wiring.

• The terminal block cover panel of the unit must be firmly attached.

• Use only accessories authorized by Mitsubishi Electric and ask a dealer or

an authorized technician to install them.

• The user should never attempt to repair the unit or transfer it to another lo-

cation.

• After installation has been completed, check for refrigerant leaks. If refriger­ant leaks into the room and comes into contact with the flame of a heater or
portable cooking range, poisonous gases will be released.

• Be sure to connect the power supply cords and the connecting wires for the
indoor units, outdoor units, and branch boxes directly to the units (no inter­mediate connections). Intermediate connections can lead to communication
errors if water enters the cords or wires and causes insufficient insulation
to ground or a poor electrical contact at the intermediate connection point.
(If an intermediate connection is necessary, be sure to take measures to
prevent water from entering the cords and wires.)

Caution:

• Make sure that the refrigerant pipes are well insulated to prevent conden­sation. Incomplete insulation may cause condensation on the surface of
pipes, wetting of the ceiling, floor and other important properties.

• Make sure that the drainage pipe is carried out correctly following this man­ual and that it is insulated in order to prevent condensation. Any deciency
caused by piping may result in water leakage, wetting of the
ceiling, oor and other personal properties.

2. Selecting a location for installation

* The branch box is only for indoor use.

Please attach the special optional cover (PAC-AK350CVR-E) to install the

branch box in the outdoors.

• Ensure that the branch box is installed in a location which facilitates servicing
and maintenance. (ensure that the required maintenance hole or service space
is available).

• Do not install near bedrooms. The sound of refrigerant owing through
the piping may sometimes be audible.

• Ensure that it is located where noise in operation will not be a problem.
After power is supplied or after an operation stop for a while, a small
clicking noise may be heard from the inside of the branch box. The elec-

tronic expansion valve is opening and closing. The unit is not faulty.

• Determine the route of refrigerant piping, drain piping, and electrical wiring be­forehand.

• Ensure that the location of the installation is such that the length of refrigerant

piping is within the specied limits.

• Ensure that the unit is out of reach of children at least 1.8 m above the oor.

• Ensure that the branch box is installed above the ceiling of corridor, bath room,
etc., where persons are not regularly there (Avoid installing at around center of
the room.) for maintenance.

• Ensure that the location of the installation is such that the down-gradient of the
drain piping is greater than 1/100.

• Do not install in location that is hot or humid for long periods of time.

* Ensure that the unit is installed in a location able to support its weight.

Warning:

Ensure that the unit is installed rmly in a location able to support its weight.
If the installation is of insufcient strength the unit may fall, resulting in injury.

 : Type A

: Type B



   













S1

S2

S3

S1

S2

S3

S1

S2

S3

S1

S2

S3

S1

S2

S3

S1

S3

S2

TB3BTB3C TB3A

TB3D

TB3E

TB2B

320



402

24













12

198

450 91

55

73

25

75 75 75 75

200

23

39

65

95

61

280 39

70

35











68

79

25 25 25 25

21

E D C B

E D C B A

A

ø20

50 34

(mm)

200

Type A

ø20

 

Type B

B

A

For use with PAC-AK52BC/PAC-AK53BC only

3

3. Conrming supplied accessories

4. Dimensions and required servicing space of branch box

PAC-AK51BC/PAC-AK52BC/PAC-AK53BC (5-branch type)

3.1. Check the Branch Box accessories and parts

Accessory name Q’ty

1

Washer (with insulation) 4

2

Washer 4

For refrigerant piping joint

Accessory name Q’ty

3

Pipe cover (Liquid) 1 TO OUTDOOR UNIT

4

Pipe cover (Gas) 1 TO OUTDOOR UNIT

5

Pipe cover (Liquid) 5 TO INDOOR UNITS

6

Pipe cover (Gas) 5 TO INDOOR UNITS

7

Joint cover (Liquid) 3

8

Joint cover (Gas) 3

9

Band 24

For drain pipe

Accessory name Q’ty

0

Drain hose 1 Type A or Type B

1

Band 2

Fig. 3-1

Optional different (deformed) joints

Fig. 4-1

* Please connect 2 indoor units or more with one system.
* 1-2 branch boxes may be connected to one outdoor unit.
* Suspension bolt : W3/8 (M10)

* Refrigerant pipe ared connection

* The piping connection size differs according to the type and capacity of

indoor units. Match the piping connection size for indoor unit and branch

box. If the piping connection size of branch box does not match the pip­ing connection size of indoor unit, use optional different-diameter (de­formed) joints to the branch box side. (Connect deformed joint directly to
the branch box side.)

* When connecting P100 indoor unit(s), attach the optional Y-shaped con

-

nection pipe to the branch box. (The Y-shaped connection pipe is intend­ed for use with PAC-AK52BC/PAC-AK53BC branch box only. )

A Suspension bolt pitch
B To indoor unit
C Flexible drain hose (Accessory)
D Drain pipe connection (VP-16)
E To outdoor unit
F Service panel (for LEV, THERMISTOR)
G 3-WIRE BAND
H Electric cover
I 3-electric wire inlet
J Terminal block (to indoor unit)
K Terminal block (to outdoor unit)
* Ensure that the branch box is installed as shown on the below drawing. Leg must

be located on top. Otherwise drainage will not be properly performed.

PAC-AK51BC/PAC-AK52BC/PAC-AK53BC (Fig.4-3)

Suspension bolt: W3/8 (M10)

Refrigerant pipe ared connection

A B C D E

To outdoor unit

Liquid pipe

ø6.35 ø6.35 ø6.35 ø6.35 ø6.35 ø9.52

Gas pipe

ø9.52 ø9.52 ø9.52 ø9.52 ø12.7 ø15.88

Drain hose size : O.D. 20 (VP16)

Model name

Connected pipe diameter Diameter A Diameter B

mm mm mm
MAC-A454JP ø9.52 → ø12.7 ø9.52 ø12.7
MAC-A455JP ø12.7 → ø9.52 ø12.7 ø9.52
MAC-A456JP ø12.7 → ø15.88 ø12.7 ø15.88
PAC-493PI ø6.35 → ø9.52 ø6.35 ø9.52
PAC-SG76RJ-E

ø9.52 → ø15.88 ø9.52

ø15.88

Fig. 4-3

Conversion formula

1/4 F ø6.35
3/8 F ø9.52
1/2 F ø12.7
5/8 F ø15.88
3/4 F ø19.05

Optional Y-shaped connection pipe for P100 indoor unit

Model name

Connected pipe diameter Diameter A Diameter B

mm mm mm

PAC-AK52YP-E

Liquid ø6.35 → ø9.52 ø6.35 ø9.52
Gas ø9.52 → ø15.88 ø9.52 ø15.88

B

A

Fig. 4-2